Vitreous enamel opacifier



Patented Mar. 10,.1936 p i UNITED STATES, PATENT OFFICE v VITREOUS QPACIFIEB e?essrsailesssfessat a Harshaw Chemical Company, Elyria, Ohio, a corporation of Ohio t No Drawing. Application April 16, 1934 Serial No. 720,806

131'3laimsl, (01. 106 -362) In the production ofenamels and the like Again, as illustrative or niixedbase compounds are heretofore, it has been "customary to employ ,noted for instance, I Y

tin oxide as a mill addition opacifler. 'Iin howcaoznosbz'ossfioz' ever ls inlimlted supply; and an opaclfier comp q r pound very generally available and ofiering an and as illustrative of partial replacement of a o extelided range of use and capable. of withstanddivalent metal by an alkali metal, .for instance ing possible abuse in firing time, is accordingly NMQZnQSbzOB3TidL a deslderatum in the art and of particular lmportance.-- Use of zirconium oxide may be illustrated for To the accomplishment of the foregoing and instance as I related ends, the invention, then, comprises the zznosbzowzrom features hereinafter fully described, and'particularly pointed out, in t m t following Both titanium and zirconium can be used description setting forth in detail certain illusgether where desired, a 1 instance trative embodiments of the invention, these be-- ing lndlcatlve however, of but a few of the variv y ous ways in which the principle of the invention These compounds are of the general formula may be emphyedzm osn oasblos In accordance with our invention, a composia tion'is made up comprising oxides of antimony i which R represents titanium o um, and of such element as titanium or zirconium, and M represents the other element. While the I and of .a base-forming element i th divalent details have not been worked out and the matter or trivalent condition, Antimony m b is merely of theoretical interest rather than of v yid'ed directly as thenentoxide; SW05, or, i any bearing on .the present case; structurally flsuafly as s o or $1,204 witn an m there is reason for believing that theb internal agent h as t oxidizf to h pentalvalent arrangement in such compounds may e v form. The titanium or zirconium is added as the oxide or in a form to yield available oxide. I Sb 8b The other metal oxide-component is advantaso 0 0- geously of zinc, or beryllium, calcium, tin, bariu'm, I u strontium, magnesium, aluminum, cerium, and where coloration is not objectionable or mi 0 wanted, manganese, lead, copper, andthe-like. o=n or A part of the divalent or trivalent element may 0 Q 0 be substituted by an alkali metal, as odiu Mn/ potassium, lithium, somewhat less desirably. n Taking a composition of zinc' oxide, antimoiw I oxide and titanium oxide for instance, beyond Sb the general optimum proportion too high a ZnO 0 .o 40

content decreases the opacity, too high a T102 I mixing content tends to run to a yellowish coloration, The composition may be made up and and too high a SbaOs content tends to lower the the calculated amounts of Sbaoa or sbzo TiOa to a paste with for instance a solution of- 5 general' the rang-e Pmlmr" 1 Zn(No3)2 calculated to give 2Zn0, and the paste tions involves 10 to 35' per cent for Zn0,30 to may be dried ground, and fired for several u per cent for SbzOs, and 25-50 per cent for at about m c, Antimony pentoxidg, s o

- V 'IiOa. A Par i y desirable Proportion is may be used of course also in a dry mix with the 6 or 22.4 per cent ZnO, 45.5 per cent SbzOs, and proportiohs.

"represented by the compound 2ZnO.Sb20s.3TiO2, other oxides, as Zn( and T102, in the desired.

p r cent Tioi. ot r notably good com- In practical operation, it is especially vsnl p unds also are for instance a in their respective proportions, and where em -2BeO.S b Os.3Ti0:, 20:10.815295311 ploylng zinc oxide dissolving half thereof in nitric 2 Sn 2-S '20s-3TlO acid, this solution serving as the wetting agent ta'geons to'proceed by weighing the components j 2 for the slip mix of the components. -By taking care to a zinc oxide tree from lead, whiteness of product is maintained. Otherwise, it lead be present, there is a tendency to yellow coloration.

-The slip mix may be made by grinding in a ball mill, and may then be dried, preferably at a temperature under 100 0., and be powdered, and the powder then be fired for several hours at about IOOQ" C. The product is a flufly white powder.

If the furnace should happen to have a reducing atmosphere; the product would run grayish. By a controlled furnace operation however, uniformly white flufly' products may be obtained.

Zinc oxide, and other oxides have long been used in enamel practice by smelting them into the frit, but it is readily apparent that combining the agents we have set forth, in the ratios shown, firing these together at suitable temperature, and employing the so-formedcompound with enamels, etc., as a mill addition, is quite a diil'erent matter, and thepresent invention makes available an opacifler or pigment of outstanding covering power capable of very economical usage.

Other modes of app ying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any oi the following claims, or the equivalent of such, be employed.

consistingof the reaction product, of an oxide of antimony, and of an oxide of an element from the group consisting of titanium and zirconium, and

of an oxide of another element from the group consisting of metals in divalent and trivalent condition, said oxides being prwent in amount'suiii cient to form a white fluify powder.

3. A vitreous enamel white opacifying agent consisting of the reaction product of an ,oxide of antimony, and of an oxide of an element from the group of titanium and zirconium, andofoxidesofmixedbasesfromthegroupcon- =sisting of metals in divalent and trivalent condition, 'said oxides being present in amount sumcient to form a white ilufly powder.

4. A vitreous enamel white opacifying agent consistingofthereactionproductofanoxideof.

antimony,andofanoxideofanelementfromthe -saidoxidesbeingpresentinammmt group consisting of titanium and zirconium, and of an oxide of another element from the group consisting of metals in divalent condition. said oxides being present inamount sufllcient to form a white fluiiy powder.

5. A vitreous enamel white opacifyingagent consisting of the reaction product of an oxide of antimony, and of an oxide of an element from the group consisting of titanium and zirconium, and

of an oxide of another element from the group consisting of zinc, beryllium, calcium and tin, said a white fluil'y powder. I I 6. A vitreous enamel white opacifying agent consisting of the reaction product of an oxide of oxides being present in amount suflicient to form antimony, and of an oxide of an element from the group consisting of titanium and zirconium, and of zinc oxide, said oxides being present in .amount sumcient to form a white flufly powder. 7. A vitreous enamel white opacii'ying agent consisting of the reaction product of an oxide of antimorm-and of an oxide of titanium, and of an 4 oxide of another element from the group consisting of metalsin divalent and trivalent condition,

suillcient to form a-white ilufiy powder. 8. A vitreous enamel white opacii'ying agent consistingioi the reaction product of an oxide of antimony, and of an oxide of titanium, and of an oxlde-ofanoth'er element from the group consista. of metals in(divalent' condition, said oxides being present in amount sufllcient to form a white fluil'y powder. Y

9. A vitreous enamel white opacifying' agent consisting of the reaction product of an oxide of antimony, and of an oxide of titanium. and of an oxide of another element from the group consisting of zinc, beryllium, calcium and tin, said oxides being present in amount sumcient to form a white fluify powder.

10. A vitreous enamel white opacifying agent consisting of the preformed reaction product 0! an oxide of antimony. and of an oxide of titanium, and of zinc oxide.

iii A vitreous enamel white opacitying agent consisting of the preformed reaction product of SbaOs 30-65 pencent, T10: 25-50 ZnO 19-35 per cent. j

12. A vitreous enamel white opacifying agent per cent, and

"of the reaction product of SbaOs about 44.5 per cent, 110: about 33.1 per cent, and ZnO about'22. 4 per cent. 13. A vitreous enamel white opacifylng agent consisting of ZZnOSb OaSTiOa. I

WILLIAM J. HARSHAW. WIILIAM D. B'I'ILLWEIL- 

